1. Field of the Invention
The disclosure of Japanese Patent Application No. 2006-104704 filed on Apr. 5, 2006, including the specification, drawings and abstract is incorporated herein by reference in its entirety.
2. Description of the Related Art
There is a known vehicular drive force distribution device that distributes the drive force generated by a drive source to right and left driving wheels. An example thereof is a vehicular drive force distribution device described in Japanese Patent Application Publication No. JP-A-11-105573. According to this technology, the drive force transmitted from the drive source is distributed to right and left driving wheels by a differential device that is made up of a planetary gear device. Furthermore, in this technology, a speed shift mechanism combining a pair of planetary gear devices is disposed adjacent to and coaxially with the differential device. The speed shift mechanism is provided with a pair of clutches for transmitting the output of the speed change mechanism selectively to a carrier and a sun gear of the differential device. By selectively putting the two clutches into slipping engagement in accordance with need at the time of cornering or the like, the drive force output via the speed shift mechanism is transmitted to the sun gear or the carrier of the differential device. The drive force is thus distributed.
However, if a limited differential motion control is to be adopted in the technology described in Japanese Patent Application Publication No. JP-A-11-105573, friction engagement elements of the two clutches have to be slid, so that the clutches need to be large in size. Furthermore, the durability of the clutches imposes a limitation. Therefore, it is substantially difficult to realize a differential motion limitation control in conjunction with the foregoing technology.